Paul,
I really makes a difference on whether your engineer is familiar with traditional timber frames (not post & beam, metal connectors). It's not something they go over in engineering school. You can still retain his/her services if you'd like, but I'd recommend getting a specialty timber frame engineer. You can look on the TF engineering council website (although they just started collecting dues, so some of their membership might be in limbo??), or in the timber frame resource guide through the Guild. Feel free to PM me as well if you'd like a personal recommendation.
Brad
